It doesn’t sound stupid at all. I typically charge a monthly retainer (to keep me/us onboard, dealing with the account reps and dealing with the client calls/emails/texts), percent on spend (launching and monitoring ads, dealing with comments, creating creatives, etc), and a performance “bonus” percentage (where we actually make the real money). I also charge flat fees for things like like UGC and landing page development with a minimum 20% mark up.
Sometimes it does vary case by case, but I always try to stick to the pricing that powers my business model. I’m also fully hands on and a lot of my clients are “big ideas” people, but have little knowledge on how to grow. Value your time, know what your worth, and charge it.
I’m always happy to help if you have a question about a client situation. DMs are open. I don’t want your money.